You don't chose who provides the electrons coming over your poles in the VAST Majority of locations (some folks run substations to multiple grids, but even then

You don't chose who provides the electrons coming over your poles in the VAST Majority of locations (some folks run substations to multiple grids, but even then, are talking to the whole other grid, not a single power company). Deregulated power is about where you send your bill, not who's producing the electrons.